import java.util.Scanner;
public class Tset {
    //按顺序输出输入的字符集合(每个字符只输出一遍)
    public static String fun(String str){
        boolean[] booleans=new boolean[255];
        StringBuilder stringBuilder=new StringBuilder();
        for (int i = 0; i <str.length() ; i++) {
            char ch=str.charAt(i);
            if(booleans[ch]==false){
                stringBuilder.append(ch);
                booleans[ch]=true;
            }

        }
        return stringBuilder.toString();
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        while (scanner.hasNextLine()){
            String str=scanner.nextLine();
            String ret=fun(str);
            System.out.println(ret);

        }
    }
}
